One purpose of this invention is to provide a microwave circulator suitable for use in flared notch antenna apertures. Currently, microstrip circulators are embedded within the flared notch housing to isolate antenna components. Suspended strip line is used to transition from microstrip to the slot line flared notch requiring three separate transmission media. For example, active array antennas utilize flared notch apertures with embedded microstrip circulators to isolate the T/R module. The low observable performance is currently limited by the existing circulator and aperture assembly tolerances.
In current designs, deviations from the manufacturing tolerances of the circulators and the aperture assembly limit the LO performance. Each transition is a source of scattering and inconsistency, both of which impact radar cross section (RCS) performance.